Movement along a Demand Curve
A movement along a demand curve is caused by the change in price factors, other things remaining the same. It is also known as the change in quantity demanded for a commodity due to change in its price, other things remaining the same. Movement is always along the same demand curve. It means that , no new demand curve is drawn. In movement a consumer moves from one point to another along the same demand curve i.e. either downward movement or upward movement.
There are two types of movement along a demand curve.
They are:-
I ) Contraction in Demand :
Other things remaining the same, when the quantity demanded for a commodity falls due to the rise in price it is called contraction in demnad. In this case, the consumer moves upward along the same demand curve which is shown by the figure below:
In the above figure, quantity demanded and price are measured along the X-axis and
Y-axis respectively. DD is a demand curve . Initially, consumer is at point 'a' on the demand curve 'DD' Where consumer purchases Q2 quantity at P1 price. When the price increases from P1 to P2, the quantity demand decreases from Q2 to Q1, this results the upward movement from point "a " to ' b ' .
II) Extension in Demand :
Other things remaining the same, when quantity for a commodity rises due to fall in price, it is called extension in demand. In this case, the consumer moves downward along the same demand curve which is shown by the following figure below.
In the above figure , the downward slopping DD curve represents the demand curve. Initially, consumer is at point 'a' on the demand curve DD when he demands Q1 quantity at P2 price. When price of the commodity falls from P2 to PI, demand increases from Q1 to Q2, this results the downward movement of the consumer from 'a ' to 'b' along the demand curve DD .
Chapter 2 Part 7
